The importance of exercise in maintaining fitness and good health is widely recognized. Exercise is important with regard to overall fitness and weight control. It helps maintain muscle tone, lubricates the joints, improves the circulation, and helps build and maintain healthy bones. Further, aerobic types of exercises, which raise the heart rate for an extended period of time, are considered vital in strengthening the heart and circulatory system. Such aerobic exercise requires constant movement of the major muscles of the body, specifically the arms and legs, for periods of time of 20 minutes or longer.
In view of the above, such exercises as swimming, bicycling, rowing, jogging, aerobic dancing, and brisk walking are in prevalent use, as aerobic exercises, because they set and maintain in motion the major muscles of the body. However, many of these exercises place considerable stress on the legs, hips, ankles, and feet of the exerciser.
The injuries to leg, hip, and foot normally suffered by athletes would prevent an athlete from engaging in exercises which stress the lower extremities and may result in severe pain and further injuries. Furthermore, persons with various diseases and illnesses, such as arthritis, rheumatism, and osteoporosis, (brittle bones) cannot engage in weight bearing exercises which, in particular, stress the lower extremities of the body including the feet, ankles, legs, knees and hips. Such exercise for these persons can often result in severe pain and injury.
Although swimming is a beneficial aerobic type of exercise which does not stress the lower extremities of the body, many persons either cannot swim or cannot swim for the extended periods of time required to obtain the benefits of aerobic exercising. For fitness of the heart, respiratory, and circulatory system, medical sports and exercising authorities recommend a minimum of aerobic exercise for 30 minute periods at least 3 to 4 times per week. In addition, exercise in water can exercise more and different muscles than are normally exercised in swimming.
Even if the exercise is not maintained for aerobic benefit, there is considerable benefit in exercising muscles to prevent atrophy and to maintain muscle tone, to prevent weakening of the bones, and to assist in the healing process in cases of injury and for the elderly and ill.
There are several existing devices for supporting humans or animals in water. U.S. Pat. No. 2,438,979 discloses a harness for bathing an animal in a bath tub. U.S. Pat. No. 2,785,055 involves a baby bath tub safety device which adapted for use in a bath tub. U.S. Pat. No. 3,835,815 provides a means for conditioning horses using a water-filled open tank with a horse and sling assembly for lifting and holding the horse in the tank while the horse swims.
A swimming pool exercise device by Eric Bass, one of the co-inventors of the present invention, in U.S. Pat. No. 4,552,540, discloses a flotation vest which is worn by an individual together with a frame. Adjustable security lines are attached between loops on the vest and anchoring loops located on the frame to further support the individual exercising in a swimming pool.
An exercise device for use in a tank containing water by Bass, U.S. Pat. No. 4,451,108 also discloses a flotation vest for use in a tank of water. Adjustable security lines are attached between loops on the vest and anchoring loops located on the tank. Thus, the exercise apparatus comprises the combination of the vest and the tank.
Although the Bass devices listed above allowed full exercise of the arms and legs without any impact or jaring on the feet, ankles, knees, legs, or hips of the exercisers (the exerciser is completely suspended in the water due to the buoyancy of the vest and the additional support of the security lines), they have several shortcomings. The vest is a single molded piece of rigid polyurethane or rigid foamed polyurethane which requires the design and use of fairly expensive molds to manufacture. Further, separate molds are required depending on the size, age, and sex of the exerciser. Also, while the individual is exercising, the vest tends to float upward, pressing against the armpits of the exerciser. Finally, the flotation vest is similar to those used as life jackets aboard airplanes and ships. These vests have greater buoyancy in the front than in the back so that one can swim with the head well supported out of the water. Thus, the tendency for a person wearing the flotation vest is to tilt, making it difficult to maintain an upright position. The security straps in the Bass patents not only help support the exerciser while floating in the tank, but in addition they maintain a verticle position for the exerciser.
Another flotation device is "The Wet Vest" by Bioenergetics of Birmingham, Alabama. This is also a full vest with arm holes for placement of the arms. More flotation material is used for the back of the device than the front which may cause a tilt off the upright position while floating. Furthermore, a belt is attached from front to back across the crotch of the exerciser to help prevent the vest from rising up relative to the body of the exerciser. The belt can be uncomfortable and could restrict motion of the exerciser.